LOS ANGELES -- Los Angeles homicide investigators refused to comment on reports they are zeroing in on a man who passed himself off as a member of the Rockefeller clan.

The Boston Globe said Thursday investigators would soon appear before a grand jury with their case against Clark Rockefeller in the disappearances of his landlords.

Los Angeles County prosecutors told the Globe this week they could not comment since grand jury proceedings in California are secret by law.

Rockefeller, whose real name is Christian Karl Geratstreiter, was arrested after a bizarre parental abduction on the East Coast last summer in which he allegedly took off with his daughter and refused to return her to his estranged wife.

The investigation revealed Geratstreiter was not a member of the high-society Rockefeller clan as he claimed, and that he had rented a room in the Los Angeles-area home of John and Linda Sohus at the same time they and another tenant vanished in the 1980s.